Utah's state fish, the native Bonneville cutthroat trout, should not be listed as a threatened or endangered species, the U.S. Fish and Wildlife Service said Tuesday.

The Center for Biological Diversity, a national conservation group, disagrees with the decision, saying it doesn't cover a broad enough range for the species or fully weigh the potential impact of global warming.

"It completely fails to consider the threat of climate change," said the center's science director, Noah Greenwald. His group will be deciding whether to challenge the decision in federal court.

Greenwald said the decision is in line with the record of the Bush administration and Interior Secretary Dirk Kempthorne, whom he accused of doing relatively little to protect new species that should be listed as threatened or endangered.

But U.S. Fish and Wildlife Service officials say there is a "viable, self-sustaining" population of the species in Utah and parts of Wyoming, Idaho and Nevada, all considered the trout's historical range. The federal agency said Bonneville cutthroat populations are being restored or protected in all watersheds where they're currently found.

"The conservation programs that state and federal agencies are involved in are doing a good job of not only providing for good restoration and conservation of the species but also keeping tabs on how the species is doing range-wide," said Paul Abate, a fisheries biologist with the U.S. Fish and Wildlife Service in Utah.

In 1979, the American Fisheries Society petitioned the federal government to list the species as threatened under the 1973 Endangered Species Act. Other groups have also petitioned for a federal listing since then.

But Eric Wagner, research director for the Utah Division of Wildlife Resources' Logan-based Fisheries Experiment Station, said most fishery biologists now believe that the fish shouldn't be listed as endangered. "I think listing at this time really isn't warranted," he said.

Annual restoration and conservation efforts by federal, state and tribal agencies are credited with keeping the trout off of the endangered list. About 153 populations of the fish can be found in about 2,061 miles of streams and 21 watersheds in four Western states.

Recreation, livestock grazing and timber harvesting are considered potential threats to the fish, but recent studies have shown that about 80 percent of the Bonneville cutthroat's habitat is in "excellent, good or fair condition."

But according to U.S. Fish and Wildlife Service data, the numbers of Bonneville cutthroat over the past 200 years have fluctuated greatly, with the more significant losses recorded in the 19th and 20th centuries. During the past 30 years, the fish populations have shown remarkable increases.

Climate change, however, along with accelerated oil and gas development in the West, have become additional potential threats that biologists have been examining. The U.S. Fish and Wildlife Service found that those activities are not currently affecting currently and will not in the foreseeable future impact Bonneville cutthroat populations.

The agency's findings were published Tuesday in the Federal Register, and documents on the subject can be found at www.fws.gov/mountain-prairie/species/fish/bct/index.htm. Abate said his agency's decision is final, and the next step will be to see if any petitioners disagree with the findings and possibly draw the issue out beyond planned ongoing conservation efforts for the species.